The present invention relates broadly to an apparatus for selectively transmitting power between a rotating shaft and a belt drive. More specifically, the present invention relates to an improved clutch assembly and integral belt brake for selectively engaging and disengaging a rotating shaft from a drive or driven belt.
In the prior art, it is common to take power from or transmit power to a rotating shaft through a V-belt which engages a pulley affixed to the shaft. A typical prior art assembly may include a driving shaft connected to a power source and having a pulley mounted thereto. A driven shaft also has a pulley affixed thereto and the rotation of the drive shaft is imparted to the driven shaft by a belt wrapped about the pulleys. The prior art apparatus include clutch mechanisms to selectively engage and disengage the drive shaft from the power source. Independent brake mechanisms have been used to stop the rotation of the driven shaft upon disengagement from the power source. Typically, the brake mechanism may include an assembly designed to frictionally engage the V-belt to bring the belt and the driven shaft to a stop. In many instances, it is important that the driven shaft be stopped within a specified period of time after power disengagement. As an example, in rotary mowers the American National Standards Institute establishes minimum requirement stopping times for rotary cutting blades. The prior art apparatus, when used in the rotary mower environment, performs within the established ANSI standards.
The present invention, however, is an improvement over the prior art apparatus in that a more rapid stopping of the driven shaft or mechanism is achieved. The present invention is also an improved assembly with an integral brake member which eliminates separate and independent clutch and brake mechanisms. The elimination of separate and independent clutch and brake devices lead to manufacturing cost reductions and reduced operator maintenance operations. Additionally, the improved stopping characteristics of the integral brake member of the present invention far exceeds present standards.